<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Db
 * @subpackage Adapter
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Sqlsrv.php 23775 2011-03-01 17:25:24Z ralph $
 */

/**
 * @see Zend_Db_Adapter_Abstract
 */
require_once 'Zend/Db/Adapter/Abstract.php';

/**
 * @see Zend_Db_Statement_Sqlsrv
 */
require_once 'Zend/Db/Statement/Sqlsrv.php';

/**
 * @category   Zend
 * @package    Zend_Db
 * @subpackage Adapter
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Db_Adapter_Sqlsrv extends Zend_Db_Adapter_Abstract {
	/**
	 * User-provided configuration.
	 *
	 * Basic keys are:
	 *
	 * username => (string) Connect to the database as this username.
	 * password => (string) Password associated with the username.
	 * dbname   => The name of the local SQL Server instance
	 *
	 * @var array
	 */
	protected $_config = array ('dbname' => null, 'username' => null, 'password' => null );
	
	/**
	 * Last insert id from INSERT query
	 *
	 * @var int
	 */
	protected $_lastInsertId;
	
	/**
	 * Query used to fetch last insert id
	 *
	 * @var string
	 */
	protected $_lastInsertSQL = 'SELECT SCOPE_IDENTITY() as Current_Identity';
	
	/**
	 * Keys are UPPERCASE SQL datatypes or the constants
	 * Zend_Db::INT_TYPE, Zend_Db::BIGINT_TYPE, or Zend_Db::FLOAT_TYPE.
	 *
	 * Values are:
	 * 0 = 32-bit integer
	 * 1 = 64-bit integer
	 * 2 = float or decimal
	 *
	 * @var array Associative array of datatypes to values 0, 1, or 2.
	 */
	protected $_numericDataTypes = array (Zend_Db::INT_TYPE => Zend_Db::INT_TYPE, Zend_Db::BIGINT_TYPE => Zend_Db::BIGINT_TYPE, Zend_Db::FLOAT_TYPE => Zend_Db::FLOAT_TYPE, 'INT' => Zend_Db::INT_TYPE, 'SMALLINT' => Zend_Db::INT_TYPE, 'TINYINT' => Zend_Db::INT_TYPE, 'BIGINT' => Zend_Db::BIGINT_TYPE, 'DECIMAL' => Zend_Db::FLOAT_TYPE, 'FLOAT' => Zend_Db::FLOAT_TYPE, 'MONEY' => Zend_Db::FLOAT_TYPE, 'NUMERIC' => Zend_Db::FLOAT_TYPE, 'REAL' => Zend_Db::FLOAT_TYPE, 'SMALLMONEY' => Zend_Db::FLOAT_TYPE );
	
	/**
	 * Default class name for a DB statement.
	 *
	 * @var string
	 */
	protected $_defaultStmtClass = 'Zend_Db_Statement_Sqlsrv';
	
	/**
	 * Creates a connection resource.
	 *
	 * @return void
	 * @throws Zend_Db_Adapter_Sqlsrv_Exception
	 */
	protected function _connect() {
		if (is_resource ( $this->_connection )) {
			// connection already exists
			return;
		}
		
		if (! extension_loaded ( 'sqlsrv' )) {
			/**
			 * @see Zend_Db_Adapter_Sqlsrv_Exception
			 */
			require_once 'Zend/Db/Adapter/Sqlsrv/Exception.php';
			throw new Zend_Db_Adapter_Sqlsrv_Exception ( 'The Sqlsrv extension is required for this adapter but the extension is not loaded' );
		}
		
		$serverName = $this->_config ['host'];
		if (isset ( $this->_config ['port'] )) {
			$port = ( integer ) $this->_config ['port'];
			$serverName .= ', ' . $port;
		}
		
		$connectionInfo = array ('Database' => $this->_config ['dbname'] );
		
		if (isset ( $this->_config ['username'] ) && isset ( $this->_config ['password'] )) {
			$connectionInfo += array ('UID' => $this->_config ['username'], 'PWD' => $this->_config ['password'] );
		}
		// else - windows authentication
		

		if (! empty ( $this->_config ['driver_options'] )) {
			foreach ( $this->_config ['driver_options'] as $option => $value ) {
				// A value may be a constant.
				if (is_string ( $value )) {
					$constantName = strtoupper ( $value );
					if (defined ( $constantName )) {
						$connectionInfo [$option] = constant ( $constantName );
					} else {
						$connectionInfo [$option] = $value;
					}
				}
			}
		}
		
		$this->_connection = sqlsrv_connect ( $serverName, $connectionInfo );
		
		if (! $this->_connection) {
			/**
			 * @see Zend_Db_Adapter_Sqlsrv_Exception
			 */
			require_once 'Zend/Db/Adapter/Sqlsrv/Exception.php';
			throw new Zend_Db_Adapter_Sqlsrv_Exception ( sqlsrv_errors () );
		}
	}
	
	/**
	 * Check for config options that are mandatory.
	 * Throw exceptions if any are missing.
	 *
	 * @param array $config
	 * @throws Zend_Db_Adapter_Exception
	 */
	protected function _checkRequiredOptions(array $config) {
		// we need at least a dbname
		if (! array_key_exists ( 'dbname', $config )) {
			/** @see Zend_Db_Adapter_Exception */
			require_once 'Zend/Db/Adapter/Exception.php';
			throw new Zend_Db_Adapter_Exception ( "Configuration array must have a key for 'dbname' that names the database instance" );
		}
		
		if (! array_key_exists ( 'password', $config ) && array_key_exists ( 'username', $config )) {
			/**
			 * @see Zend_Db_Adapter_Exception
			 */
			require_once 'Zend/Db/Adapter/Exception.php';
			throw new Zend_Db_Adapter_Exception ( "Configuration array must have a key for 'password' for login credentials.
                                                If Windows Authentication is desired, both keys 'username' and 'password' should be ommited from config." );
		}
		
		if (array_key_exists ( 'password', $config ) && ! array_key_exists ( 'username', $config )) {
			/**
			 * @see Zend_Db_Adapter_Exception
			 */
			require_once 'Zend/Db/Adapter/Exception.php';
			throw new Zend_Db_Adapter_Exception ( "Configuration array must have a key for 'username' for login credentials.
                                                If Windows Authentication is desired, both keys 'username' and 'password' should be ommited from config." );
		}
	}
	
	/**
	 * Set the transaction isoltion level.
	 *
	 * @param integer|null $level A fetch mode from SQLSRV_TXN_*.
	 * @return true
	 * @throws Zend_Db_Adapter_Sqlsrv_Exception
	 */
	public function setTransactionIsolationLevel($level = null) {
		$this->_connect ();
		$sql = null;
		
		// Default transaction level in sql server
		if ($level === null) {
			$level = SQLSRV_TXN_READ_COMMITTED;
		}
		
		switch ($level) {
			case SQLSRV_TXN_READ_UNCOMMITTED :
				$sql = "READ UNCOMMITTED";
				break;
			case SQLSRV_TXN_READ_COMMITTED :
				$sql = "READ COMMITTED";
				break;
			case SQLSRV_TXN_REPEATABLE_READ :
				$sql = "REPEATABLE READ";
				break;
			case SQLSRV_TXN_SNAPSHOT :
				$sql = "SNAPSHOT";
				break;
			case SQLSRV_TXN_SERIALIZABLE :
				$sql = "SERIALIZABLE";
				break;
			default :
				require_once 'Zend/Db/Adapter/Sqlsrv/Exception.php';
				throw new Zend_Db_Adapter_Sqlsrv_Exception ( "Invalid transaction isolation level mode '$level' specified" );
		}
		
		if (! sqlsrv_query ( $this->_connection, "SET TRANSACTION ISOLATION LEVEL $sql;" )) {
			require_once 'Zend/Db/Adapter/Sqlsrv/Exception.php';
			throw new Zend_Db_Adapter_Sqlsrv_Exception ( "Transaction cannot be changed to '$level'" );
		}
		
		return true;
	}
	
	/**
	 * Test if a connection is active
	 *
	 * @return boolean
	 */
	public function isConnected() {
		return (is_resource ( $this->_connection ) && (get_resource_type ( $this->_connection ) == 'SQL Server Connection'));
	}
	
	/**
	 * Force the connection to close.
	 *
	 * @return void
	 */
	public function closeConnection() {
		if ($this->isConnected ()) {
			sqlsrv_close ( $this->_connection );
		}
		$this->_connection = null;
	}
	
	/**
	 * Returns an SQL statement for preparation.
	 *
	 * @param string $sql The SQL statement with placeholders.
	 * @return Zend_Db_Statement_Sqlsrv
	 */
	public function prepare($sql) {
		$this->_connect ();
		$stmtClass = $this->_defaultStmtClass;
		
		if (! class_exists ( $stmtClass )) {
			/**
			 * @see Zend_Loader
			 */
			require_once 'Zend/Loader.php';
			Zend_Loader::loadClass ( $stmtClass );
		}
		
		$stmt = new $stmtClass ( $this, $sql );
		$stmt->setFetchMode ( $this->_fetchMode );
		return $stmt;
	}
	
	/**
	 * Quote a raw string.
	 *
	 * @param string $value     Raw string
	 * @return string           Quoted string
	 */
	protected function _quote($value) {
		if (is_int ( $value )) {
			return $value;
		} elseif (is_float ( $value )) {
			return sprintf ( '%F', $value );
		}
		
		return "'" . str_replace ( "'", "''", $value ) . "'";
	}
	
	/**
	 * Gets the last ID generated automatically by an IDENTITY/AUTOINCREMENT column.
	 *
	 * As a convention, on RDBMS brands that support sequences
	 * (e.g. Oracle, PostgreSQL, DB2), this method forms the name of a sequence
	 * from the arguments and returns the last id generated by that sequence.
	 * On RDBMS brands that support IDENTITY/AUTOINCREMENT columns, this method
	 * returns the last value generated for such a column, and the table name
	 * argument is disregarded.
	 *
	 * @param string $tableName   OPTIONAL Name of table.
	 * @param string $primaryKey  OPTIONAL Name of primary key column.
	 * @return string
	 */
	public function lastInsertId($tableName = null, $primaryKey = null) {
		if ($tableName) {
			$tableName = $this->quote ( $tableName );
			$sql = 'SELECT IDENT_CURRENT (' . $tableName . ') as Current_Identity';
			return ( string ) $this->fetchOne ( $sql );
		}
		
		if ($this->_lastInsertId > 0) {
			return ( string ) $this->_lastInsertId;
		}
		
		$sql = $this->_lastInsertSQL;
		return ( string ) $this->fetchOne ( $sql );
	}
	
	/**
	 * Inserts a table row with specified data.
	 *
	 * @param mixed $table The table to insert data into.
	 * @param array $bind Column-value pairs.
	 * @return int The number of affected rows.
	 */
	public function insert($table, array $bind) {
		// extract and quote col names from the array keys
		$cols = array ();
		$vals = array ();
		foreach ( $bind as $col => $val ) {
			$cols [] = $this->quoteIdentifier ( $col, true );
			if ($val instanceof Zend_Db_Expr) {
				$vals [] = $val->__toString ();
				unset ( $bind [$col] );
			} else {
				$vals [] = '?';
			}
		}
		
		// build the statement
		$sql = "INSERT INTO " . $this->quoteIdentifier ( $table, true ) . ' (' . implode ( ', ', $cols ) . ') ' . 'VALUES (' . implode ( ', ', $vals ) . ')' . ' ' . $this->_lastInsertSQL;
		
		// execute the statement and return the number of affected rows
		$stmt = $this->query ( $sql, array_values ( $bind ) );
		$result = $stmt->rowCount ();
		
		$stmt->nextRowset ();
		
		$this->_lastInsertId = $stmt->fetchColumn ();
		
		return $result;
	}
	
	/**
	 * Returns a list of the tables in the database.
	 *
	 * @return array
	 */
	public function listTables() {
		$this->_connect ();
		$sql = "SELECT name FROM sysobjects WHERE type = 'U' ORDER BY name";
		return $this->fetchCol ( $sql );
	}
	
	/**
	 * Returns the column descriptions for a table.
	 *
	 * The return value is an associative array keyed by the column name,
	 * as returned by the RDBMS.
	 *
	 * The value of each array element is an associative array
	 * with the following keys:
	 *
	 * SCHEMA_NAME      => string; name of schema
	 * TABLE_NAME       => string;
	 * COLUMN_NAME      => string; column name
	 * COLUMN_POSITION  => number; ordinal position of column in table
	 * DATA_TYPE        => string; SQL datatype name of column
	 * DEFAULT          => string; default expression of column, null if none
	 * NULLABLE         => boolean; true if column can have nulls
	 * LENGTH           => number; length of CHAR/VARCHAR
	 * SCALE            => number; scale of NUMERIC/DECIMAL
	 * PRECISION        => number; precision of NUMERIC/DECIMAL
	 * UNSIGNED         => boolean; unsigned property of an integer type
	 * PRIMARY          => boolean; true if column is part of the primary key
	 * PRIMARY_POSITION => integer; position of column in primary key
	 * IDENTITY         => integer; true if column is auto-generated with unique values
	 *
	 * @todo Discover integer unsigned property.
	 *
	 * @param string $tableName
	 * @param string $schemaName OPTIONAL
	 * @return array
	 */
	public function describeTable($tableName, $schemaName = null) {
		/**
		 * Discover metadata information about this table.
		 */
		$sql = "exec sp_columns @table_name = " . $this->quoteIdentifier ( $tableName, true );
		$stmt = $this->query ( $sql );
		$result = $stmt->fetchAll ( Zend_Db::FETCH_NUM );
		
		// ZF-7698
		$stmt->closeCursor ();
		
		if (count ( $result ) == 0) {
			return array ();
		}
		
		$owner = 1;
		$table_name = 2;
		$column_name = 3;
		$type_name = 5;
		$precision = 6;
		$length = 7;
		$scale = 8;
		$nullable = 10;
		$column_def = 12;
		$column_position = 16;
		
		/**
		 * Discover primary key column(s) for this table.
		 */
		$tableOwner = $result [0] [$owner];
		$sql = "exec sp_pkeys @table_owner = " . $tableOwner . ", @table_name = " . $this->quoteIdentifier ( $tableName, true );
		$stmt = $this->query ( $sql );
		
		$primaryKeysResult = $stmt->fetchAll ( Zend_Db::FETCH_NUM );
		$primaryKeyColumn = array ();
		
		// Per http://msdn.microsoft.com/en-us/library/ms189813.aspx,
		// results from sp_keys stored procedure are:
		// 0=TABLE_QUALIFIER 1=TABLE_OWNER 2=TABLE_NAME 3=COLUMN_NAME 4=KEY_SEQ 5=PK_NAME
		

		$pkey_column_name = 3;
		$pkey_key_seq = 4;
		foreach ( $primaryKeysResult as $pkeysRow ) {
			$primaryKeyColumn [$pkeysRow [$pkey_column_name]] = $pkeysRow [$pkey_key_seq];
		}
		
		$desc = array ();
		$p = 1;
		foreach ( $result as $key => $row ) {
			$identity = false;
			$words = explode ( ' ', $row [$type_name], 2 );
			if (isset ( $words [0] )) {
				$type = $words [0];
				if (isset ( $words [1] )) {
					$identity = ( bool ) preg_match ( '/identity/', $words [1] );
				}
			}
			
			$isPrimary = array_key_exists ( $row [$column_name], $primaryKeyColumn );
			if ($isPrimary) {
				$primaryPosition = $primaryKeyColumn [$row [$column_name]];
			} else {
				$primaryPosition = null;
			}
			
			$desc [$this->foldCase ( $row [$column_name] )] = array ('SCHEMA_NAME' => null, // @todo
'TABLE_NAME' => $this->foldCase ( $row [$table_name] ), 'COLUMN_NAME' => $this->foldCase ( $row [$column_name] ), 'COLUMN_POSITION' => ( int ) $row [$column_position], 'DATA_TYPE' => $type, 'DEFAULT' => $row [$column_def], 'NULLABLE' => ( bool ) $row [$nullable], 'LENGTH' => $row [$length], 'SCALE' => $row [$scale], 'PRECISION' => $row [$precision], 'UNSIGNED' => null, // @todo
'PRIMARY' => $isPrimary, 'PRIMARY_POSITION' => $primaryPosition, 'IDENTITY' => $identity );
		}
		
		return $desc;
	}
	
	/**
	 * Leave autocommit mode and begin a transaction.
	 *
	 * @return void
	 * @throws Zend_Db_Adapter_Sqlsrv_Exception
	 */
	protected function _beginTransaction() {
		if (! sqlsrv_begin_transaction ( $this->_connection )) {
			require_once 'Zend/Db/Adapter/Sqlsrv/Exception.php';
			throw new Zend_Db_Adapter_Sqlsrv_Exception ( sqlsrv_errors () );
		}
	}
	
	/**
	 * Commit a transaction and return to autocommit mode.
	 *
	 * @return void
	 * @throws Zend_Db_Adapter_Sqlsrv_Exception
	 */
	protected function _commit() {
		if (! sqlsrv_commit ( $this->_connection )) {
			require_once 'Zend/Db/Adapter/Sqlsrv/Exception.php';
			throw new Zend_Db_Adapter_Sqlsrv_Exception ( sqlsrv_errors () );
		}
	}
	
	/**
	 * Roll back a transaction and return to autocommit mode.
	 *
	 * @return void
	 * @throws Zend_Db_Adapter_Sqlsrv_Exception
	 */
	protected function _rollBack() {
		if (! sqlsrv_rollback ( $this->_connection )) {
			require_once 'Zend/Db/Adapter/Sqlsrv/Exception.php';
			throw new Zend_Db_Adapter_Sqlsrv_Exception ( sqlsrv_errors () );
		}
	}
	
	/**
	 * Set the fetch mode.
	 *
	 * @todo Support FETCH_CLASS and FETCH_INTO.
	 *
	 * @param integer $mode A fetch mode.
	 * @return void
	 * @throws Zend_Db_Adapter_Sqlsrv_Exception
	 */
	public function setFetchMode($mode) {
		switch ($mode) {
			case Zend_Db::FETCH_NUM : // seq array
			case Zend_Db::FETCH_ASSOC : // assoc array
			case Zend_Db::FETCH_BOTH : // seq+assoc array
			case Zend_Db::FETCH_OBJ : // object
				$this->_fetchMode = $mode;
				break;
			case Zend_Db::FETCH_BOUND : // bound to PHP variable
				require_once 'Zend/Db/Adapter/Sqlsrv/Exception.php';
				throw new Zend_Db_Adapter_Sqlsrv_Exception ( 'FETCH_BOUND is not supported yet' );
				break;
			default :
				require_once 'Zend/Db/Adapter/Sqlsrv/Exception.php';
				throw new Zend_Db_Adapter_Sqlsrv_Exception ( "Invalid fetch mode '$mode' specified" );
				break;
		}
	}
	
	/**
	 * Adds an adapter-specific LIMIT clause to the SELECT statement.
	 *
	 * @param string $sql
	 * @param integer $count
	 * @param integer $offset OPTIONAL
	 * @return string
	 * @throws Zend_Db_Adapter_Sqlsrv_Exception
	 */
	public function limit($sql, $count, $offset = 0) {
		$count = intval ( $count );
		if ($count <= 0) {
			require_once 'Zend/Db/Adapter/Exception.php';
			throw new Zend_Db_Adapter_Exception ( "LIMIT argument count=$count is not valid" );
		}
		
		$offset = intval ( $offset );
		if ($offset < 0) {
			/** @see Zend_Db_Adapter_Exception */
			require_once 'Zend/Db/Adapter/Exception.php';
			throw new Zend_Db_Adapter_Exception ( "LIMIT argument offset=$offset is not valid" );
		}
		
		if ($offset == 0) {
			$sql = preg_replace ( '/^SELECT\s/i', 'SELECT TOP ' . $count . ' ', $sql );
		} else {
			$orderby = stristr ( $sql, 'ORDER BY' );
			
			if (! $orderby) {
				$over = 'ORDER BY (SELECT 0)';
			} else {
				$over = preg_replace ( '/\"[^,]*\".\"([^,]*)\"/i', '"inner_tbl"."$1"', $orderby );
			}
			
			// Remove ORDER BY clause from $sql
			$sql = preg_replace ( '/\s+ORDER BY(.*)/', '', $sql );
			
			// Add ORDER BY clause as an argument for ROW_NUMBER()
			$sql = "SELECT ROW_NUMBER() OVER ($over) AS \"ZEND_DB_ROWNUM\", * FROM ($sql) AS inner_tbl";
			
			$start = $offset + 1;
			$end = $offset + $count;
			
			$sql = "WITH outer_tbl AS ($sql) SELECT * FROM outer_tbl WHERE \"ZEND_DB_ROWNUM\" BETWEEN $start AND $end";
		}
		
		return $sql;
	}
	
	/**
	 * Check if the adapter supports real SQL parameters.
	 *
	 * @param string $type 'positional' or 'named'
	 * @return bool
	 */
	public function supportsParameters($type) {
		if ($type == 'positional') {
			return true;
		}
		
		// if its 'named' or anything else
		return false;
	}
	
	/**
	 * Retrieve server version in PHP style
	 *
	 * @return string
	 */
	public function getServerVersion() {
		$this->_connect ();
		$serverInfo = sqlsrv_server_info ( $this->_connection );
		
		if ($serverInfo !== false) {
			return $serverInfo ['SQLServerVersion'];
		}
		
		return null;
	}
}
